Tendinitis (Tendonitis)

What happens in tendinitis

Tendons transmit force from muscles to bones. When they are loaded more than they can adapt to, through repetitive movements, a sudden increase in training, or poor technique, tiny areas of damage develop. In early or acute cases, there is an inflammatory response. In longer-lasting cases, the tendon shows degenerative changes (disorganized collagen and new blood vessels) with little inflammation. This is why many specialists now use the term tendinopathy, and why rest alone often does not fix it: tendons need gradual loading to remodel and strengthen.

Common types of tendinitis

Symptoms

• pain at the tendon, worse with movement or activity and easing with rest
• tenderness when pressing on the tendon
• stiffness, especially in the morning or after rest (common in Achilles tendinopathy)
• mild swelling or thickening
• a creaking or grating feeling in some tendons
• weakness from pain

Causes and risk factors

• repetitive movements at work, sport or hobbies
• a sudden increase in training volume or intensity
• poor technique or equipment, such as heavy rackets or worn shoes
• aging, as tendons lose elasticity
• tight or weak muscles
• obesity
• conditions such as diabetes, rheumatoid arthritis, gout, thyroid disease and kidney disease
• fluoroquinolone antibiotics, which increase the risk of tendinitis and rupture, especially in people over 60 or taking steroids
• steroid injections into or near tendons

Diagnosis

Tendinitis is usually diagnosed by history and examination: locating tenderness and reproducing pain with specific movements against resistance. Imaging is used when the diagnosis is unclear, symptoms persist, or a tear is suspected:

• ultrasound: shows tendon thickening, tears and fluid
• MRI: detailed view of tendon and nearby structures
• X-ray: shows calcium deposits (calcific tendinitis) or bone spurs
• blood tests if gout or inflammatory arthritis is possible

Treatment

Load management

• reduce or modify the activity that causes pain, but do not stop moving completely
• pain during exercise up to about 3 to 5 out of 10, settling within 24 hours, is usually acceptable
• adjust technique, equipment and workstation setup

Exercise therapy

This is the most effective long-term treatment:

• isometric exercises (holding a contraction) can reduce pain early on
• progressive strengthening, including eccentric and heavy slow resistance exercises, rebuilds tendon capacity
• stretching and flexibility for surrounding muscles
• a physical therapist can tailor a program, typically for 8 to 12 weeks or longer

Pain relief

• ice for 15 minutes after activity can ease pain
• NSAIDs, oral or topical gels, for short-term relief. Follow the label dose and avoid oral NSAIDs with stomach ulcers, kidney disease or heart failure
• acetaminophen (paracetamol)

Other treatments

• braces or straps, such as a forearm strap for tennis elbow or a thumb splint for De Quervain's
• corticosteroid injections: effective short-term for some types, such as De Quervain's and trigger finger, but may delay recovery in tennis elbow and are generally avoided in the Achilles and patellar tendons because of rupture risk
• extracorporeal shock wave therapy for persistent cases, such as calcific shoulder tendinitis or Achilles tendinopathy
• platelet-rich plasma injections have mixed evidence
• surgery is rarely needed, mainly for tears or cases that fail many months of treatment

Prevention

• increase training gradually, no more than about 10 percent a week
• warm up and cool down
• use good technique and suitable equipment
• strengthen and stretch the muscles around joints
• take breaks from repetitive tasks
• ask about alternatives to fluoroquinolones if you are at higher risk

Frequently asked questions

What is the difference between tendinitis and tendonitis?

There is no difference. Both spellings refer to the same condition: pain and irritation of a tendon. Doctors increasingly use "tendinopathy" because long-standing cases involve tendon degeneration more than inflammation.

How long does tendinitis take to heal?

Mild tendinitis often improves in 2 to 6 weeks. More persistent tendinopathy usually needs 3 to 6 months of a structured exercise program. Returning to full activity too quickly is a common cause of setbacks.

Should I rest or exercise with tendinitis?

Both, in balance. Reduce the activity that aggravates the tendon, but keep it moving. Gradual strengthening exercises are the most effective treatment, because tendons need loading to heal. Complete rest weakens tendons further.

Is ice or heat better for tendinitis?

Ice helps reduce pain after activity, especially early on. Heat can relax stiff muscles before exercise in long-standing cases. Neither cures tendinitis on its own. Exercise therapy is the key treatment.

Can tendinitis lead to a tendon rupture?

It can, especially in the Achilles tendon, rotator cuff and biceps, and in people taking fluoroquinolone antibiotics or after repeated steroid injections. A sudden pop with loss of strength needs prompt medical assessment.